By PETER T. KILBORN

           MIAMI, Feb. 18 -- A high-ranking United States immigration
           official was charged in federal court today with spying for the
          Cuban government, after federal officials said he was caught in an
          elaborate sting passing on what he thought was classified information
          about a Cuban's plan to defect to the United States.

          The man, Mariano M. Faget, who was born in Havana and left Cuba in
          his teens, is a senior official in the Miami field office of the Immigration
          and Naturalization Service. Mr. Faget, who is 54, was arrested here late
          Thursday. The immigration service and the Federal Bureau of
          Investigation say they caught him last week passing along to an otherwise
          unidentified "Cuban-born New York businessman" false information they
          had fed him about a Cuban intelligence agent's plan to defect to the
          United States.

          Mr. Faget was charged with violations of the Espionage Act and lying to
          federal agents.

          The Cuban Interests Section in Washington, in a statement, denied the
          allegations..

          Private individuals have been convicted of spying for Cuba, but federal
          officials said they knew of no prior instance of the arrest of an American
          government official.

          "I've been here for 24 years," said Terry Nelson, an F.B.I. spokesman,
          "and I can't recall ever arresting a government official -- especially an
          official with such access to immigrant records."

          As section chief for adjudications and the third-ranking officer in the
          Miami office, Mr. Faget (pronounced fah-HAY) had access to classified
          files and the authority to treat applications for political asylum. Thus, he
          was in a position to tell Havana of the plans of Cuban nationals to defect
          and subject them to retaliation.

          The investigation is continuing and officials said they did not know of
          defections Mr. Faget might have blocked. "It's too early to tell if he did
          any damage or what kind of damage he did," said Carlos Zaldivar, a
          lawyer in the Miami office of the F.B.I.

          Mr. Faget, who was scheduled to retire in March, made a telephone call,
          recorded by the F.B.I., on Feb. 14 to the New York businessman, then
          visiting Beijing. In the call, Mr. Faget said he had nothing new to report
          about the Cuban spy.

          In an affidavit filed with the charges against Mr. Faget, Joe Franklin, an
          agent for the F.B.I. in Miami, wrote: "The businessman concluded the call
          by asking Faget, 'You're still not leaving until next month, right?' Faget
          answered, 'Until next month. Yes. We have time.' "

          The arrest is likely to stir the pot of Cuban-American relations, already
          boiling because of the custody battle over 6-year-old Elián González,
          who survived his mother's drowning when she fled Cuba with him in
          November. Elián's relatives here are fighting in court for custody against
          the wishes of his father in Cuba.

          "When I found out about this, I laughed," said Jose Basulto, president of
          Brothers to the Rescue, a Cuban exile group that supports the relatives.
          "I'm sure there are many more spies out there, hundreds, even thousands.
          This should really come in handy for Elián's situation."

          In the statement today, the Cuban Interests Section called the allegations
          "a colossal and false slander," and said, "We are sure that it is no
          coincidence that these false accusations are surfacing during a critical
          moment for the return of little Elián to his father."

          The cases are unrelated and investigation of Mr. Faget began more than
          a year ago, officials said. Maria Cardona, a spokeswoman for the
          immigration service, said Mr. Faget "has never been involved in the Elián
          González case."

          At a news conference here and in a court affidavit, immigration and
          F.B.I. officials and the United States attorney, Thomas E. Scott,
          described a year of investigating Mr. Faget after suspicions were raised
          by a routine investigation.

          Last year, investigators say, they observed Mr. Faget meeting with a
          Cuban intelligence officer for 90 minutes at Pitchers Bar in the Miami
          Marriott Hotel and with a second officer for two hours in a secluded area
          of the lobby of the Hilton Hotel in Miami. Mr. Faget never disclosed the
          meetings to his superiors, the investigators reported. He was also not
          authorized to meet the agents on immigration service business, but the
          government did not report whether the men discussed immigration
          matters.

          If found guilty on all the charges, he faces at least 10 years in prison and
          a $250,000 fine. Mr. Faget, who is being held in the Federal Detention
          Center here, could not be reached for comment, and no one answered
          the phone at his home.

          A woman at the office of his lawyer, Joel Kaplan, said Mr. Kaplan was
          unavailable.

          Mr. Faget spent 34 years with the immigration service, climbing the ranks
          from an entry-level clerical job. In 1971, official records show, he
          married Pitty Sanchez, who is also called Maria and is 52. To all
          appearances, they live modestly in a white, two-story tract house in the
          Amaretto subdivision in Kendall, southwest of Miami.